PARIS - A gas leak at a factory in France left a strong odor over Paris and large areas in the western part of the country early on Tuesday, police said.A police official told Reuters that a leak of mercaptan gas from a factory in Rouen, 120 kilometres (75 miles) west of Paris, was responsible for the smell. He added there was no danger to the public.A second police official in Paris said authorities were being flooded with calls from worried residents in the French capital.A news website, Tendanceouest, said the leak was from a Lubrizol plant that makes oil additives. The website said the sulfur smell from the gas was causing migraines, irritations and nausea around Rouen.Several Paris residents reported a very strong odor of diesel fuel.